Wim and me, we have been working on updating the MMPM subsystem so that it will finally support WAV files with 24-bit and > 65535 Hz (there was a limitation in the MMPM subsystem components that would restrict the sample rate to a 16-bit value).

In fact, we updated the MMPM subsystem to support these sample rates beyond 48000 Hz:64000, 88200,96000,176400,192000,352800,384000 Hz.

The MMPM subsystem still has an inherent limitation to only support a discrete number of sample rates but we picked the rates that are in common use today. But I think we can live with that and the supported rates can be extended if necessary (but will require an updated USBAUDIO installation, see end).

With this support you can finally use more recent USB audio devices and exploit their full capabilities.While 16-bit, 44100 Hz stereo (CD-ROM quality) was about the best you could get in 1996, more than 20 years later this is about the minimum sample rate /bit-depth used. It will also pave the way to support USB audio 2.0 devices which normally only offer these higher sample rates.

By the way: UNIAUD would also need this MMPM subsystem update to support WAV files with sample rates higher than 48000 Hz.

Once we have everything nice and polished I will release a new version of my USB device drivers.It will be necessary to rerun the USBAUDIO driver installation to get everything updated properly.

In principle, yes. But I don't see the concept of multiple simultaneous streams supported in the USB audio spec. And therefore the current installation restricts it to 1 stream. But thinking about it, maybe yes, I'll have to check if there are devices that support multiple interfaces with each having the same parameters.What DOES work is having a simultaneous input (record) and output (playback stream).

This is pretty awesome stuff. Will this make for a completely separate solution from something like the AN stuff though?

Thanks, - Dariusz

Don't worry. You can combine my USBAUDIO.SYS with the AN driver stack and it should work just fine. The updated installation installs a new dll called USBAUDIF.DLL as a replacement for AUDIOIF.DLL alongside to the already existing AUDIOIF.DLL (in the \MMOS2\DLL dir) but it leaves AUDIOIF.DLL untouched so they don't step on each others toes.

Likewise the new installation overwrites SPI.INI (in the \MMOS2 dir) but our SPI ini update is "cumulative", which means it includes and adds on top of what is already in the default SPI.INI file.

In short: we try to keep things compatible with whatever comes with an AN installation.

Are the additional sample rates available to any audio adapter, or just USB?

Just wondering - I've got a couple of Warp boxes running audio logging 24x7, I'd love to be able to up the sample rate (they're using onboard audio cards supported via Uniaudio).

I could of course switch these 2 systems over to using USB audio cards if needed.

Currently they are only available to USBAUDIO because the USBAUDIO installation package updates the MMPM subsystem accordingly.The problem is an outdated AUDIOIF.DLL and SPI.INI. In principle Uniaudio could also support these higher rates and BitsPerSample (of course only if the HW supports them). But for that it needs an updated AUDIOIF.DLL and SPI.INI.In order to not interfere with other audio adapters we have decided to build a USBAUDIF.DLL which takes the place of AUDIOIF.DLL so that AUDIOIF.DLL can remain untouched.

I got ther recvomended USB audio adapter9Ugreen) but, I have run minstall and it stil does not work. is there anything eslse I need todo?

After running "minstall /*" you needed to reboot your system. I assume that you have done that.May be you did not remove the installation of an existing audio card and therefore you have right now 2 audio devices installed.Check your "Multimedia Setup" which is in the map "System Setup" to verify that you have the "USB Adapter Wave" and the "USB Adapter MIDI" tabs available.Make these the default devices and reboot your system.

I have always 2 audio devices installed on my systems and I do it in a different way.After running "minstall /*" and reboot I edit MMPM2.INI and make sure that it contains the following section: